I was surprised, to say the least, when it came upon me that here, on the edge of Hyogo and Osaka prefectures, in my daily life in Japan, I am now using more English than when I was living in Auckland, New Zealand

Like many English-speaking foreigners to Japan, I have taken up work in a language school, and my girlfriend, while Japanese, speaks English.

I must say that my Japanese is of a fairly good level, conversational and otherwise, but I just can't seem to find anywhere to use it outside of trips to the konbini

Any ideas for a gaijin looking to speak more Japanese, even only on my day off?

Join any kind of club or lesson. There are tons of things to do in the Kansai. Find something you enjoy that isn't language oriented, like a sport or club at your local community center. You can meet lots of people who share your interests and are not only looking for a free English lesson. A lot of Japanese people will really want to speak English with you so making friends with people who either a: Have zero interest in English, or b: are fluent enough that they don't fee the need to practice their English on you any chance they get is best.

Another good way to meet people (and the way I met a lot of people who still are my good friends now after 10 years in the Kansai) is frequent a small local restaurant with lots of regulars. Become a regular yourself and start up a conversation with someone you've seen a few times. Good food and good times.

frequent a small local restaurant with lots of regulars. Become a regular yourself

I second both of those. Not only will you have a lot more opportunities to use Japanese, I think you'll have a richer Japanese experience in general. Joining a martial arts dojo or a tea ceremony school, for example, will teach you more about uchi vs. soto and the sempai/kohai system than reading a book (or, worse, the internet). By extension, when you leave Japan you'll be left with an overall much deeper and daresay more authentic impression, for better or worse.

Just keep in mind that you are going to have to go out and make these experiences happen for yourself. Japan and Japanese aren't going to come teach themselves to you. On the flip side, the deeper you go the more you'll find your Japanese isn't as good as you thought it was but the more potential you'll have to make it better.

I have never been to Japan so I can't comment from experience but in Spain and Italy I used to talk to the shop assistants everywhere I went, restaurant owners - anyone I met really in my daily life. I lived in Spain and Italy firstly employed myself and secondly as the wife of someone working there - neither times working in a language school. I found out about local groups and started doing Tai Chi, entirely in Spanish (no-one spoke or wished to speak English).

EDIT: I had this problem totally, I studied in Japan being around tons of English speaking foreigners and numerous Japanese friends that spoke perfect English. You have to take the insinuative, its not easy. Fortunately my girlfriend in Japan didn't speak much English but outside of that all friends spoke perfect English but also were either fluent in Japanese or were able to speak it well. Its easy to fall into doing whats natural, but you don't have to go outside of that in order to try and speak Japanese with people who are able to. Its starts with you... again, its not easy, but you can do it.

EDIT EDIT: Also I'm very surprised that you being in the Osaka area that so many people can speak/want to speak English. I did not have that same experience most of the time.

Hmm, yeah, I guess I'll have to go out of my way a little bit. I used to think it crazy that people could spend years and years in Japan and not learn the language, but I guess that it is actually a common trap to fall into, especially if you are an English teacher.

Good news is, I have a few Japanese friends who I met in my home country who I can meet up with and rap away in Japanese.

yes i think it is okay to speak english in japan sometimes. likewise to lordoftheflies respond in japanese. similarly in hong kong many people speak english but if someone speaks in CHINESE we will respond accordingly

I think it's all in who you hang out with. If you spend most of your time in a school teaching English, then of course you aren't going to hear much Japanese. That would be like someone in a school in America teaching Spanish. You probably will hear a lot more Spanish than English. I would join a martial arts class or other classes or clubs. Spend more time walking around and visiting shops and restaurants where you'll find more Japanese spoken.